wrong js code when using ts constructor assignment

Bug Report

• I would like to work on a fix!

Current Behavior If a module imported from TypeScript has the same name as a constructor parameter, a bug occurs.

Input Code

• REPL or Repo link if applicable:
  • babeljs repl
  • typescript repl

import { messaging } from 'firebase-admin'

export class Something {
  constructor(
  	public messaging: messaging.Messaging
  ) {
  }
}

Expected behavior/code

Expected,

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.Something = void 0;

class Something {
  constructor(messaging) {
    this.messaging = messaging;
  }

}

exports.Something = Something;

But actual,

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.Something = void 0;

var _firebaseAdmin = require("firebase-admin");

class Something {
  constructor(_firebaseAdmin.messaging) { // Whoops!
    this.messaging = messaging;
  }

}

exports.Something = Something;

Babel Configuration (babel.config.js, .babelrc, package.json#babel, cli command, .eslintrc)

• Filename: .babelrc

{
  "presets": [
    ["@babel/env", {
      "targets": "maintained node versions",
      "useBuiltIns": "usage",
      "corejs": 3
    }],
    "@babel/typescript"
  ]
}

Environment

  System:
    OS: macOS 10.15.2
  Binaries:
    Node: 10.16.3 - ~/.nvm/versions/node/v10.16.3/bin/node
    Yarn: 1.17.3 - /usr/local/bin/yarn
    npm: 6.9.0 - ~/.nvm/versions/node/v10.16.3/bin/npm
  npmPackages:
    @babel/cli: ^7.8.3 => 7.8.3
    @babel/core: ^7.8.3 => 7.8.3
    @babel/plugin-proposal-class-properties: ^7.8.3 => 7.8.3
    @babel/plugin-proposal-decorators: ^7.8.3 => 7.8.3
    @babel/plugin-proposal-object-rest-spread: ^7.8.3 => 7.8.3
    @babel/plugin-proposal-optional-chaining: ^7.8.3 => 7.8.3
    @babel/preset-env: ^7.8.3 => 7.8.3
    @babel/preset-typescript: ^7.8.3 => 7.8.3
    eslint: ^6.2.2 => 6.2.2
    jest: ^24.9.0 => 24.9.0

• Babel version(s): 7.8.3
• Node/npm version: node 10.16.3 / npm 6.9.0
• OS: macOS 10.15.2
• Monorepo: no
• How you are using Babel: cli

Possible Solution

Additional context/Screenshots .

[sidntrivedi012]

Sorry for delaying the work on this issue. Will start working on it from today onwards.

[dangreaves]

I experienced a very similar issue to this when importing a type with the same name as the constructor argument. However, in my case, the output was slightly different to the above, resulting in a module import.

Source

import { S3EventRecord } from "aws-lambda";

export class SapFileCreated {
  constructor(protected S3EventRecord: S3EventRecord) {}
}

Expected output

class SapFileCreated {
  constructor(S3EventRecord) {
    this.S3EventRecord = S3EventRecord;
  }
}

Actual output

var _awsLambda = __webpack_require__(246);

class SapFileCreated {
  constructor(S3EventRecord) { // S3EventRecord is ignored here
    this.S3EventRecord = _awsLambda.S3EventRecord;
  }
}

Versions

• @babel/core 7.9.0
• @babel/preset-env 7.9.0
• @babel/preset-typescript 7.9.0